Why can’t I use my apple gift card I have $20 on it can’t even use what’s is going on

I have absolutely no idea what your response means.

You must redeem your Apple Gift Card to use it. I don’t know if you did this.

How to redeem your Apple Gift Card or App Store & iTunes gift card - Apple Support

And I still cannot imagine what your response means.

I have redeem my card but why can’t I Fucking purchase my game currency wtf 🤬 why can’t purchase while I am buying a 10 dollar when I have 20 dollar in balance wtf

Did you redeem the card?

Then what did you attempt to purchase? What did you see? What messages appeared? What other relevant facts have you omitted?